The present invention relates to a treatment for imparting excellent water repellency, oil repellency and soil releasability to a textile. A method of the present invention is particularly useful for a carpet.
Hitherto, various treatment methods have been proposed in order to impart water repellency, oil repellency and soil releasability to a textile such as a carpet. For example, a process (hereinafter, sometimes referred to as xe2x80x9cExhaust processxe2x80x9d) of treating a textile comprising decreasing a pH of a treatment liquid, applying the treatment liquid to the textile, thermally treating the textile with steam, washing the textile with water, and dehydrating the textile is proposed.
A method comprising the Exhaust process is proposed in U.S. Pat. Nos. 5,073,442, 5,520,962, 5,516,337 and 5,851,595 and International Publication WO 98/50619.
U.S. Pat. No. 5,073,442 discloses a method of treating a textile, comprising conducting an Exhaust process by using a water- and oil-repellent agent comprising a fluorine-containing compound, a formaldehyde condensation product and an acrylic polymer. U.S. Pat. Nos. 5,520,962 and 5,851,595 disclose a method of treating a carpet, comprising conducting an Exhaust process by using a fluorine-containing compound and a polymeric binder. U.S. Pat. No. 5,516,337 discloses a method of treating a textile, comprising conducting an Exhaust process by using a fluorine-containing water- and oil-repellent agent and a metal compound such as aluminum sulfate. International Publication WO 98/50619 discloses a method of treating a carpet, comprising conducting an Exhaust process by using a fluorine-containing water- and oil-repellent agent and a salt such as a magnesium salt.
JP-A-2000-144119 discloses a water-based soil release agent composition which comprises fine particles of a fluorine-containing copolymer comprising a (meth)acrylate having a polyfluoroalkyl group, an alkyl acrylate ester and a (meth)acrylate monoester of polyol, and a water-based medium. However, the use of the Exhaust process is not described, and a substrate treated with said water-based soil release agent composition is poor in water repellency, oil repellency and soil releasability.
Hitherto, a treatment agent satisfying both of excellent water- and oil-repellency and excellent soil releasability by using the Exhaust process could not be obtained.
An object of the present invention is to give a textile excellent in water repellency, oil repellency and soil releasability, when the textile is treated with a water- and oil-repellent agent by an Exhaust process.
The present invention provides a method of preparing a treated textile, comprising steps of:
(1) preparing a treatment liquid comprising a water- and oil-repellent agent,
(2) adjusting pH of the treatment liquid to at most 7,
(3) applying the treatment liquid to a textile,
(4) treating the textile with steam, and
(5) washing the textile with water and dehydrating the textile,
wherein the water- and oil-repellent agent comprises (A) a fluorine-containing compound which is a fluorine-containing polymer, and (B) a urethane compound and/or (C) a silicon-containing compound.
The present invention also provides a textile prepared by the above-mentioned method and a water- and oil-repellent agent used in the above-mentioned method.
The procedure used in the present invention is an Exhaust process which comprises decreasing pH of a treatment liquid comprising a fluorine-containing compound, applying a treatment liquid to a textile, thermally treating the textile, washing the textile with water, and dehydrating the textile.
In the step (1) of the method of the present invention, the treatment liquid comprising the water- and oil-repellent agent, which is applied to the textile, is prepared. The treatment liquid comprising the water- and oil-repellent agent may be in the form of a solution or an emulsion, particularly an aqueous emulsion.
In the step (2) in the method of the present invention, pH of the treatment liquid is brought to at most 7. pH of the treatment liquid is, for example, at most 5, e.g., at most 4, particularly at most 3, especially at most 2. pH can be decreased by addition of an acid such as an aqueous solution of citraconic acid and an aqueous solution of sulfamic acid to the treatment liquid.
In the step (3) of the method of the present invention, the treatment liquid is applied to the textile. The water- and oil-repellent agent can be applied to a substrate to be treated (that is, the textile) by a know procedure. The application of the treatment liquid can be conducted by immersion, spraying and coating. Usually, the treatment liquid is diluted with an organic solvent or water, and is adhered to surfaces of the substrate by a well-known procedure such as an immersion coating, a spray coating and a foam coating to a fabric (for example, a carpet cloth), a yarn (for example, a carpet yarn) or an original fiber. If necessary, the treatment liquid is applied together with a suitable crosslinking agent, followed by curing. It is also possible to add mothproofing agents, softeners, antimicrobial agents, flame retardants, antistatic agents, paint fixing agents, crease-proofing agents, etc. to the treatment liquid. The concentration of the water- and oil-repellent agent active component (that is, the fluorine-containing compound) in the treatment liquid contacted with the substrate may be from 0.01 to 10% by weight, for example, from 0.05 to 10% by weight, based on the treatment liquid. A stain blocking agent may used in the amount of, for example, 0 to 1,000 parts by weight, particularly 1 to 500 parts by weight, in terms of solid, per 100 parts by weight of the fluorine-containing compound.
In the step (4) of the method of the present invention, the textile is thermally treated. The thermal treatment can be conducted by applying a steam (for example, 90 to 110xc2x0 C.) to the textile under a normal pressure for e.g., 10 seconds to 10 minutes.
In the step (5) of the method of the present invention, the textile is washed with water and dehydrated. The thermally treated textile is washed with water at least once. Then, in order to remove excess water, the textile is dehydrated by a usual dehydration procedure such as a centrifuging and vacuuming procedure.
After the step (5), the textile can be dried.
The fluorine-containing compound is a fluorine-containing polymer.
The fluorine-containing polymer may be a polymer comprising a repeat unit derived from a fluoroalkyl group-containing monomer such as a fluoroalkyl group-containing (meth)acrylate, a fluoroalkyl group-containing maleate or fumarate, or a fluoroalkyl group-containing urethane.
The fluoroalkyl group-containing (meth)acrylate ester may be of the formula:
Rfxe2x80x94Axe2x80x94OCOCR11xe2x95x90CH2
wherein Rf is a fluoroalkyl group having 3 to 21 carbon atoms, R11 is a hydrogen atom or a methyl group, and A is a divalent organic group.
In the above formula, A may be a linear or branched alkylene group having 1 to 20 carbon atoms, a xe2x80x94SO2N(R21)R22xe2x80x94 group or a xe2x80x94CH2CH(OR23)CH2xe2x80x94 group (R21 is an alkyl group having 1 to 10 carbon atoms, R22 is a linear or branched alkylene group having 1 to 10 carbon atoms, and R23 is a hydrogen atom or an acyl group having 1 to 10 carbon atoms).
Examples of the fluoroalkyl group-containing (meth)acrylate are as follows: xe2x80x83Rfxe2x80x94(CH2)nOCOCR3xe2x95x90CH2xe2x80x83xe2x80x83(2)
xe2x80x83Rfxe2x80x94Oxe2x80x94Arxe2x80x94CH2OCOCR3xe2x95x90CH2xe2x80x83xe2x80x83(6)
wherein Rf is a fluoroalkyl group having 3 to 21 carbon atoms, R1 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R2 is an alkylene group having 1 to 10 carbon atoms, R3 is a hydrogen atom or a methyl group, and Ar is arylene group optionally having a substituent, and n is an integer of 1 to 10.
Specific examples of the fluoroalkyl group-containing (meth)acrylate are as follows:
CF3(CF2)7(CH2)10OCOCHxe2x95x90CH2 
CF3(CF2)7(CH2)10OCOC(CH3)xe2x95x90CH2 
CF3(CF2)6CH2OCOCHxe2x95x90CH2 
CF3(CF2)8CH2OCOC(CH3)xe2x95x90CH2 
(CF3)2CF(CF2)6(CH2)2OCOCHxe2x95x90CH2 
(CF3)2CF(CF2)8(CH2)2OCOCHxe2x95x90CH2 
(CF3)2CF(CF2)10(CH2)2OCOCHxe2x95x90CH2 
(CF3)2CF(CF2)6(CH2)2OCOC(CH3)xe2x95x90CH2 
(CF3)2CF(CF2)8(CH2)2OCOC(CH3)xe2x95x90CH2 
(CF3)2CF(CF2)10(CH2)2OCOC(CH3)xe2x95x90CH2 
CF3CF2(CF2)6(CH2)2OCOCHxe2x95x90CH2 
CF3CF2(CF2)8(CH2)2OCOCHxe2x95x90CH2 
CF3CF2(CF2)10(CH2)2OCOCHxe2x95x90CH2 
CF3CF2(CF2)6(CH2)2OCOC(CH3)xe2x95x90CH2 
CF3CF2(CF2)8(CH2)2OCOC(CH3)xe2x95x90CH2 
CF3CF2(CF2)10(CH2)2OCOC(CH3)xe2x95x90CH2 
CF3(CF2)7SO2N(CH3)(CH2)2OCOCHxe2x95x90CH2 
CF3(CF2)7SO2N(C2H5)(CH2)2OCOCHxe2x95x90CH2 
(CF3)2CF(CF2)8CH2CH(OCOCH3)CH2OCOC(CH3)xe2x95x90CH2 
(CF3)2CF(CF2)6CH2CH(OH)CH2OCOCHxe2x95x90CH2 
The fluorine-containing polymer constituting the water- and oil-repellent agent may comprise:
(I) a repeat unit derived from a monomer having a fluoroalkyl group, and
(II) a repeat unit derived from a fluorine-free monomer.
The fluorine-containing polymer constituting the water- and oil-repellent agent may comprise:
(I) a repeat unit derived from a monomer having a fluoroalkyl group,
(II) a repeat unit derived from a fluorine-free monomer, and
(III) a repeat unit derived from a crosslinkable monomer.
Examples of the monomer having fluoroalkyl group constituting the repeat unit (I) include the same as the above-mentioned fluoroalkyl group-containing monomer such as a fluoroalkyl group-containing (meth)acrylate.
The repeat unit (II) is preferably derived from a fluorine-free olefinically unsaturated monomer.
An example of the repeat unit (II) is one derived from olefinically unsaturated monomer of the formula (II-A):
CH2xe2x95x90CR21C(xe2x95x90O)xe2x80x94Oxe2x80x94CH2xe2x80x94CR22Hxe2x80x94R23xe2x80x83xe2x80x83(II-A)
or the formula (II-B):
CH2xe2x95x90CR21C(xe2x95x90O)xe2x80x94Oxe2x80x94R23xe2x80x83xe2x80x83(II-B)
wherein R21 is CH3 or H, R22 is CH3 or C2H5, and R23 is CnH2n+1 (n=1 to 30, particularly 1 to 6).
In the fluorine-containing polymer, the amount of the repeat unit (II-A) is from 5 to 75 parts by weight and the amount of (II-B) is from 0 to 50, based on 100 parts by weight of the repeat unit (I).
Non-limiting examples of a preferable monomer constituting the repeat unit (II) include, for example, ethylene, vinyl acetate, vinyl halide such as vinyl chloride, vinylidene halide such as vinylidene chloride, acrylonitrile, styrene, polyethyleneglycol (meth)acrylate, polypropyleneglycol (meth)acrylate, methoxypolyethyleneglycol (meth)acrylate, methoxypolypropyleneglycol (meth)acrylate, vinyl alkyl ether and isoprene.
The monomer constituting the repeat unit (II) may be a (meth)acrylate ester having an alkyl group. The number of carbon atoms of the alkyl group may be from 1 to 30, for example, from 6 to 30, e.g., from 10 to 30. For example, the monomer constituting the repeat unit (II) may be acrylates of the general formula:
CH2xe2x95x90CA3COOA4
wherein A3 is a hydrogen atom or a methyl group, and A4 is an alkyl group represented by CnH2n+1 (n=1 to 30). The copolymerization with this monomer can optionally improve various properties such as water repellency and soil releasability; cleaning durability, washing durability and abrasion resistance of said repellency and releasability; solubility in solvent; hardness; and feeling.
The crosslinkable monomer constituting the repeat unit (III) may be a fluorine-free vinyl monomer having at least two reactive groups. The crosslinkable monomer may be a compound having at least two carbon-carbon double bonds, or a compound having at least one carbon-carbon double bond and at least one reactive group.
Examples of the crosslinkable monomer include diacetoneacrylamide, (meth)acrylamide, N-methylolacrylamide, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, butadiene, chloroprene and glycidyl (meth)acrylate, to which the crosslinkable monomer is not limited. The copolymerization with this monomer can optionally improve various properties such as water repellency and soil releasability; cleaning durability and washing durability of said repellency and releasability; solubility in solvent; hardness; and feeling.
The fluorine-containing polymer may have a weight-average molecular weight of 2,000 to 5,000,000, particularly 3,000 to 5,000,000, especially 10,000 to 1,000,000.
Preferably, in the fluorine-containing polymer, the amount of the repeat unit (II) is from 0 to 80 parts by weight, more preferably from 0 to 60 parts by weight, for example, from 0.5 to 50 parts by weight, and the amount of the repeat unit (III) is from 0 to 30 parts by weight, more preferably from 0.5 to 15 parts by weight, for example, from 0.5 to 10 parts by weight, based on 100 parts by weight of the repeat unit (I).
The fluorine-containing polymer in the present invention can be produced by any polymerization method, and the conditions of the polymerization reaction can be arbitrary selected. The polymerization method includes, for example, solution polymerization and emulsion polymerization. Among them, the emulsion polymerization is particularly preferred.
In the solution polymerization, there can be used a method of dissolving monomers into an organic solvent in the presence of a polymerization initiator, replacing the atmosphere by nitrogen, and stirring the mixture with heating, for example, at the temperature within the range from 50xc2x0 C. to 120xc2x0 C. for 1 hour to 10 hours. Examples of the polymerization initiator include azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate and diisopropyl peroxydicarbonate. The polymerization initiator may be used in the amount within the range from 0.01 to 5 parts by weight based on 100 parts by weight of the monomers.
The organic solvent is inert to the monomer and dissolves the monomer, and examples thereof include pentane, hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, petroleum ether, tetrahydrofuran, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, trichloroethylene, perchloroethylene, tetrachlorodifluoroethane and trichlorotrifluoroethane. The organic solvent may be used in the amount within the range from 50 to 1,000 parts by weight based on 100 parts by weight of total of the monomers.
In the emulsion polymerization, there can be used a method of emulsifying monomers in water in the presence of a polymerization initiator and an emulsifying agent, replacing the atmosphere by nitrogen, and copolymerizing with stirring, for example, at the temperature within the range from 50xc2x0 C. to 80xc2x0 C. for 1 hour to 10 hours. As the polymerization initiator, for example, water-soluble initiators (e.g., benzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate, 1-hydroxycyclohexyl hydroperoxide, 3-carboxypropionyl peroxide, acetyl peroxide, azobisisobutylamidine dihydrochloride, azobisisobutyronitrile, sodium peroxide, potassium persulfate and ammonium persulfate) and oil-soluble initiators (e.g., azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate and diisopropyl peroxydicarbonate) are used. The polymerization initiator may be used in the amount within the range from 0.01 to 5 parts by weight based on 100 parts by weight of the monomers.
In order to obtain a copolymer dispersion in water, which is superior in storage stability, it is desirable that the monomers are atomized in water by using an emulsifying device capable of applying a strong shattering energy (e.g., a high-pressure homogenizer and an ultrasonic homogenizer) and then polymerized with using the oil-soluble polymerization initiator. As the emulsifying agent, various emulsifying agents such as an anionic emulsifying agent, a cationic emulsifying agent and a nonionic emulsifying agent can be used in the amount within the range from 0.5 to 10 parts by weight based on 100 parts by weight of the monomers. When the monomers are not completely compatibilized, a compatibilizing agent capable of sufficiently compatibilizing them (e.g., a water-soluble organic solvent and a low-molecular weight monomer) is preferably added to these monomers. By the addition of the compatibilizing agent, the emulsifiability and copolymerizability can be improved.
Examples of the water-soluble organic solvent include acetone, methyl ethyl ketone, ethyl acetate, propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol, tripropylene glycol and ethanol. The water-soluble organic solvent may be used in the amount within the range from 1 to 50 parts by weight, e.g., from 10 to 40 parts by weight, based on 100 parts by weight of water.
The amount of the fluorine-containing compound may be at most 80% by weight, particularly from 1 to 60% by weight, based on the water- and oil-repellent agent. The amount of the emulsifying agent may be from 0.5 to 15 parts by weight, based on 100 parts by weight of the fluorine-containing compound.
The urethane compound (B) is a low molecular weight compound having at least one urethane group. The number of urethane groups in the urethane compound is, for example, 1 to 10, particularly from 2 to 4. The molecular weight of the urethane compound (B) is, for example, from 500 to 4,000, particularly from 2,000 to 3,000.
The urethane compound (B) is, for example, a compound of the formula:
(Rfxe2x80x2xe2x80x94COxe2x80x94NH)aX(NHxe2x80x94COxe2x80x94Rxe2x80x2)b
wherein Rfxe2x80x2 is a monovalent organic group having at least one fluorine atom,
X is an organic group having a valency of (a+b) remaining after all isocyanate groups are removed from an isocyanate compound having (a+b) isocyanate groups,
Rxe2x80x2 is a monovalent organic group free of a fluorine atom, and
a is an integer of 0 to 10, b is an integer of from 0 to 10, and the total of a and b is an integer of 1 to 15.
The number a may be, for example, from 0 to 4, particularly from 0 to 2. The number b may be, for example, from 0 to 4, particularly from 0 to 2. The total of the numbers a and b may be, for example, from 1 to 10, particularly from 1 to 5, especially from 2 to 4.
The Rfxe2x80x2 group may be, for example, a group:
Rfxe2x80x94A1xe2x80x94B1xe2x80x94
wherein Rf is a fluoroalkyl group (particularly perfluoroalkyl group) having 3 to 21 carbon atoms,
A1 is xe2x80x94SO2xe2x80x94N(R11)xe2x80x94R12xe2x80x94, xe2x80x94(CH2)nxe2x80x94, xe2x80x94COxe2x80x94N(R11)xe2x80x94, xe2x80x94CH2C(OH)HCH2xe2x80x94, xe2x80x94CH2C(OCOR13)HCH2xe2x80x94, or xe2x80x94Oxe2x80x94Arxe2x80x94CH2xe2x80x94 (in which R11 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R12 is alkylene group having 1 to 10 carbon atoms, R13 is a hydrogen atom or a methyl group, and Ar is an arylene group optionally having a substituent), and
B1 is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R21)xe2x80x94 (in which R21 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms).
The Rxe2x80x2 group may be, for example, a group:
xe2x80x94B2xe2x80x94A2
wherein B2 is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R21)xe2x80x94 (in which R21 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms), and
A2 is an optionally substituted alkyl group having 1 to 30 carbon atoms (for example, a stearyl group).
The urethane compound (B) is, for example, a compound of the formula:
(Rfxe2x80x94A1xe2x80x94B1xe2x80x94COxe2x80x94NH)aX (NHCOxe2x80x94B2xe2x80x94A2)b
wherein each of Rf, A1, B1, X, B2 and A2 is independently the same as the above, and a and b are the same as the above.
Specific examples of the urethane compound (B) are as follows. 
wherein Rf, A2 and B2 are the same as the above.
The urethane compound (B) can be obtained by reacting an isocyanate compound with an isocyanate-reactive compound. The isocyanate-reactive compound is, for example, a compound having at least one (particularly one) hydroxyl group, amino group or epoxy group.
The isocyanate compound may be a compound of the formula:
X(NCO)a+b,
and
the isocyanate-reactive compound may be a compound of the formula:
Rfxe2x80x94A1xe2x80x94B1xe2x80x94H
(a fluorine-containing isocyanate-reactive compound) and/or
Hxe2x80x94B2xe2x80x94A2
(a fluorine-free isocyanate-reactive compound)
wherein Rf, A1, B1, X, B2, A2, a and b are the same as the above.
Examples of the isocyanate compound are as follows: 
(that is, a homopolymer of hexamethylene diisocyanate) (p is a number of 0 to 10.), 
wherein R11 is divalent aliphatic, cycloaliphatic, aromatic or araliphatic hydrocarbon group (having, for example, 1 to 20 carbon atoms, particularly 1 to 10 carbon atoms). 
Specific examples of the fluorine-containing isocyanate-reactive compound having one hydroxyl group, amino group or epoxy group is as follows:
CF3CF2(CF2CF2)nCH2CH2OH
CF3CF2(CF2CF2)nCH2CH2NH2

[n=2 to 8]
[n=2 to 8]
Specific examples of the fluorine-free isocyanate-reactive compound are as follows:
R41xe2x80x94OH
R42xe2x80x94NH2 
wherein R41, R42 and R43 are an alkyl group having 1 to 22 carbon atoms.
Specific examples of the silicon-containing compound (C) are as follows:
Silicone Oils 
wherein n is an integer of 1 to 100,000,
Modified Silicones 
wherein A is a direct bond or an alkylene group having 1 to 20 carbon atoms, X is an epoxy group, an amine group, a carboxyl group, an aryl group or a hydroxyl group, and a and b is an integer of 1 to 100,000, and
Silicone Resin 
wherein R is an aliphatic hydrocarbon group (for example, a methyl group) or an aromatic hydrocarbon group (for example, an aryl group), and n is an integer of 1 to 100,000.
The total amount of the urethane compound (B) and the silicon-containing (C) may be, for example, from 1 to 30% by weight, particularly from 1 to 20% by weight, based on the water- and oil-repellent agent.
The substrate to be treated in the present invention is preferably a textile, particularly a carpet. The textile includes various examples. Examples of the textile include animal- or vegetable-origin natural fibers such as cotton, hemp, wool and silk; synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride and polypropylene; semisynthetic fibers such as rayon and acetate; inorganic fibers such as glass fiber, carbon fiber and asbestos fiber; and a mixture of these fibers. The present invention can be suitably used in carpets made of nylon fibers, polypropylene fibers and/or polyester fibers, because the present invention provides excellent resistance to a detergent solution and brushing (mechanical).
The textile may be in any form such as a fiber and a fabric. When the carpet is treated according to the present invention, the carpet may be formed after the fibers or yarns are treated with the water- and oil-repellent agent, or the formed carpet may be treated with the water- and oil-repellent agent. The water- and oil-repellent agent can be used under the state that the fluorine-containing compound is diluted to 0.02% to 30% by weight, preferably 0.02% to 10% by weight.